Study On In-situ Measurement Method Of Heat Transfer Coefficient Of Building Envelop

Energy saving is an important issue which has a vital bearing on the safey and healthy development of human society. It is an inevitable choice for duration development. Building energy efficiency (BEE) is now a significant subject in the building field. The BEE task in our country has developed for about 20 years and has achieved some improvements,but it's still in a difficult position at present.For instance, the lagging of the in-situ measurement technology has influence on the implement of the BEE.There are three methods of in-situ measurement of heat transfer coefficient of building envelopes:heat flow meter method,hot box method,unsteady state method.But they all have their own shortage.Thus,to study in-situ measurement method is in urgent demand in BEE task.In this paper,the temperature controlled box heat flow meter method is studied.Taking heat flow meter method as it's basic measurement,using hot box to make an enviorment which is the same as the condition period.The method combines the advantages of heat flow and hot box method.It's not restricted by the season,and it's unnecessary to rectify the error of hot box.In this paper,the mathematics physics equation of heat transfer in building envelopes is established.The heat transfer process was simulately investigated using numerical analysis to confirm the validity of mathematic model.Then,the heat transfer performence of some materials and walls were measured in laboratory using this mathod.The heat transfer coefficient of one construction was also measured in-situ in different season.The results were compared with hot box method and heat flow method respectively.It can be found that our method can measure the heat transfer coefficient precisely.Furthermore,the measuement can be well repeated and is not influenced by the season.